Treatment of obesity by sub-diaphragmatic nerve stimulation

ABSTRACT

A method and apparatus for treating obese or other patients with compulsive overeating disorder includes unilaterally or bilaterally stimulating one or both of the left and right branches of a patient&#39;s vagus nerve directly or indirectly with an electrical pulse signal generated by an implantable neurostimulator with at least one operatively coupled nerve electrode to apply the pulse signal to the selected nerve branch at a location below the patient&#39;s diaphragm. The implantable neurostimulator is programmable to enable physician programming of electrical and timing parameters of the pulse signal, to induce weight loss of the patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is related to U.S. application Ser. No.09/346,396, filed Jul. 1, 1999 (referred to elsewhere in thisapplication as “the '396 application”), assigned to the same assignee asthe present application.

BACKGROUND OF THE INVENTION

[0002] The present invention relates generally to methods and apparatusfor treating eating disorders by application of modulating electricalsignals to a selected cranial nerve, nerve branch or nerve bundle, andmore particularly to techniques for treating patients with overeatingdisorders, especially obese patients, by application of such signalsunilaterally or bilaterally to the patient's vagus nerve with one ormore neurostimulating devices.

[0003] Increasing prevalence of obesity is one of the most serious andwidespread health problems facing the world community. It is estimatedthat, currently, about 6% of the total population of the United Statesis morbidly obese and a much larger percentage is either obese orsignificantly overweight. Morbid obesity is defined as having a bodymass index of more than forty, or, as is more commonly understood, beingmore than one hundred pounds overweight for a person of average height.Aside from what may be an epidemic of obesity, it is believed by manyhealth experts that obesity is one of the first two leading causes ofpreventable deaths in the United States, either ahead of or just behindcigarette smoking. or not that is an accurate assessment, studies haveindicated that morbid obesity dramatically increases health care costs.It is a major cause of adult onset diabetes in the United States, up toapproximately eighty percent of the cases. It may be a leading factor inas many as ninety percent of sleep apnea cases. Obesity is also asubstantial risk factor for coronary artery disease, stroke, chronicvenous abnormalities, numerous orthopedic problems and esophageal refluxdisease. Researchers have documented a link between obesity, infertilityand miscarriages, as well as post menopausal breast cancer.

[0004] The classical treatment option for obese people combinesnutritional counseling with exercise and education, but has demonstratedrelatively little long term success. Liquid diets and pharmaceuticalagents can bring about acute, but not lasting weight loss. Surgicalprocedures for either gastric restriction or malabsorption in cases ofsevere obesity have shown the greatest success long-term, but are majorsurgery that can lead to emotional problems, and have their share offailures (e.g., Kriwanek, “Therapeutic failures after gastric bypassoperations for morbid obesity,” Langenbecks Archiv. Fur Chirurgie,38(2): 70-74, 1995).

[0005] U.S. Pat. No. 5,263,480 to J. Wemicke et al., assigned to thesame assignee as the present application, discloses treatment for eatingdisorders including obesity and compulsive overeating disorder byselectively applying modulating electrical signals to the patient'svagus nerve, preferably using an implanted neurostimulator. Modulatingsignals may be used to stimulate vagal activity to increase the flow ofneural impulses up the nerve, or to inhibit vagal activity to blockneural impulses from moving up the nerve, toward the brain, forproducing excitatory or inhibitory neurotransmitter release.

[0006] Both of these cases of modulating the electrical activity of thevagus nerve have been termed vagus nerve stimulation, or VNS. The '480patent theorized that VNS could be used for appetite suppression bycausing the patient to experience satiety, a sensation of “fullness” ofthe stomach which would result in decreased food consumption andconsequent weight reduction. For example, the stimulus generator of theneurostimulator is implanted in a convenient location in the patient'sbody, attached to an electrical lead having a nerve electrode implantedon the vagus nerve or branch thereof in the esophageal region slightlyabove the stomach. If the patient's food consumption over a given periodexceeded a predetermined threshold level, detected and measured forexample by sensing electrodes implanted at or near the esophagus, thestimulus generator is triggered to apply VNS and thereby induce satiety.Alternatively, VNS is applied periodically during the patient's normalwaking hours except in periods of prescribed mealtimes, or is applied asa result of patient intervention by manual activation of the stimulusgenerator using external magnet control. Patient intervention assumes apatient with an earnest desire to control his or her eating behavior,but normally lacking will power to control the compulsive behaviorwithout the support of VNS.

[0007] Like most of the pairs of cranial nerves, the tenth cranialnerve, the vagus, originates from the brain stem. It passes throughforamina of the skull to parts of the head, neck and trunk. The vagus isa mixed nerve, with both sensory and motor fibers, the sensory fibersbeing primary and attached to neuron cell bodies located outside thebrain in ganglia groups, and the motor fibers attached to neuron cellbodies located within the gray matter of the brain. The vagus, as acranial nerve, is part of the peripheral nervous system or PNS whosenerves branch out from the central nervous system (CNS) to connect theCNS to other body parts. Somatic fibers of the cranial nerves areinvolved in conscious activities and connect the CNS to the skin andskeletal muscles, while autonomic fibers of these nerves are involved inunconscious activities and connect the CNS to the visceral organs suchas the heart, lungs, stomach, liver, pancreas, spleen, and intestines.

[0008] The motor fibers of the vagus nerve transmit impulses to themuscles associated with speech and swallowing, the heart, and smoothmuscles of the visceral organs of the thorax and abdomen. In contrast,its sensory fibers transmit impulses from the pharynx, larynx, esophagusand visceral organs of the thorax and abdomen. The vagus is split intoleft and right branches, or left and right vagi, which run respectivelythrough the left and right sides of the neck and trunk. It is the axialportion of the body, which includes the head, neck and trunk with whichwe are primarily concerned in respect of the present invention. Theventral cavity of the axial portion contains visceral organs andincludes the thoracic cavity and the abdominopelvic cavity, which areseparated by the diaphragm, a broad thin muscle. Visceral organs in thethoracic cavity include the right and left lungs, the heart, theesophagus, the trachea and the the thymus gland. Below the diaphragm, inthe abdominopelvic cavity and specifically the upper abdominal portionor abdominal portion, the visceral organs therein include the stomach,liver, spleen, gall bladder, and majority of the small and largeintestines.

[0009] The vagus nerve is the dominant nerve of the gastrointestinal(GI) tract, the right and left branches or nerve afferents of the vagusconnecting the GI tract to the brain. After leaving the spinal cord, thevagal afferents transport information regarding that tract to the brain.In the lower part of the chest, the left vagus rotates, becomes theanterior vagus, and innervates the stomach. The right vagus rotates tobecome the posterior vagus, which branches into the celiac division andinnervates the duodenum and proximal intestinal tract.

[0010] The exact mechanisms leading an individual to satiety are notfully known, but a substantial amount of information has beenaccumulated. Satiety signals include the stretch of mechanoreceptors,and the stimulation of certain chemosensors (e.g., “A Protective Rolefor Vagal Afferents: An Hypothesis,” Neuroanatomy and Physiology ofAbdominal Vagal Afferents, Chapter 12, CRC Press, 1992). These signalsare transported to the brain by the nervous system or endocrine factorssuch as gut peptides (e.g., “External Sensory Events and the Control ofthe Gastrointestinal Tract: An Introduction” id. at Chapter 5). It hasbeen demonstrated that direct infusion of maltose and oleic acid intothe duodenum of rats leads to a reduction in food intake, and that theresponse is ablated by vagotomy or injection of capsaicin, whichdestroys vagal afferents. Introduction of systemic cholecystokinin alsoreduces intake in rats, and is ablated by destruction of vagalafferents.

[0011] While the vagus is often considered to be a motor nerve whichalso carries secretory signals, 80% of the nerve is sensory consistingof afferent fibers (e.g., Grundy et al., “Sensory afferents from thegastrointestinal tract,” Handbook of Physiology, Sec. 6, S. G., Ed.,American Physiology Society, Bethesda, Md., 1989, Chapter 10).

[0012] The aforementioned '396 application discloses a method oftreating patients for obesity by bilateral stimulation of the patient'svagus nerve (i.e., bilateral VNS) in which a stimulating electricalsignal is applied to one or both branches of the vagus. The parametersof the signal are predetermined to induce weight loss of the patient.The signal is preferably a pulse signal applied at a set duty cycle(i.e., its on and off times) intermittently to both vagi. In any event,VNS is applied at a supra-diaphragmatic position (i.e., above thediaphragm) in the ventral cavity. The electrical pulse stimuli are setat a current magnitude below the retching level of the patient (e.g.,not exceeding about 6 milliamperes (mA), to avoid patient nausea) inalternating periods of continuous application and no application. Pulsewidth is set at or below 500 microseconds (μs), and pulse repetitionfrequency at about 20-30 Hz. The on/off duty cycle (i.e., firstperiod/second period of the alternating periods) is programmed to aratio of about 1:1.8. The neurostimulator, which may be a single deviceor a pair of devices, is implanted and electrically coupled to lead(s)having nerve electrodes implanted on the right and left branches of thevagus.

SUMMARY OF THE INVENTION

[0013] According to the present invention, a method of treating patientsfor obesity comprises unilateral or bilateral stimulation of the leftand right vagi at a sub-diaphragmatic position (i.e., below thediaphragm) in the ventral cavity, rather than at a supra-diaphragmaticposition as taught by the '396 application. The stimulating electricalsignal is preferably applied to the vagus two to three inches below thediaphragm, and may be applied either synchronously or asynchronously toboth the right and left branches, preferably in the form of a series ofpulses applied intermittently to both branches according to apredetermined on/off duty cycle. The intermittent application ispreferably chronic, rather than acute. However, continuous applicationor acute application by bilateral stimulation of the right and left vagior unilateral stimulation of either branch, at the sub-diaphragmaticposition, is also contemplated.

[0014] The sub-diaphragmatic application of VNS may have an enhancedeffect in inducing satiety in the patient, being in closer proximity tothe stomach itself. Certainly, in the case of neurostimulator deviceimplantation superficially in the abdominal region of the patient, thesub-diaphragmatic application has an advantage of enabling shorter leadsfor the nerve electrode(s). Additionally, application of theneurostimulator may be more easily accomplished with this approach asopposed to a supra-diaphragmatic approach which requires accessing thevagi in the chest cavity.

[0015] Acute application of the stimulating electrical signal to theright and left vagi during a customary mealtime, or from a short timepreceding and/or following the mealtime, according to the patient'scircadian cycle, may be effective in certain cases. Automatic deliveryof bilateral intermittent stimulation is preferred, but it isalternatively possible to control application of the stimulatingelectrical signal to the right and left vagi by an external commencementsignal produced by the patient's placement of an external magnet, or byanother patient-applied signal, in proximity to the location of theimplanted device.

[0016] Preferably, the same stimulating electrical signal is applied toboth the right and left vagi, but as an alternative, a stimulatingelectrical signal might be applied to the right vagus which is differentfrom the stimulating electrical signal applied to the left vagus. Andalthough two separate nerve stimulator generators may be implanted forstimulating the left and right vagi, respectively, as an alternative asingle nerve stimulator generator may be implanted for bilateralstimulation if the same signal is to be applied to both the left andright branches of the vagus nerve, whether, delivered synchronously orasynchronously to the vagi.

[0017] As with the method disclosed in the '396 application, the currentmagnitude of the stimulating signal is programmed to be less than about6 mA, and in any case is held below the retching level of the patient asdetermined by the implanting physician at the time the implant procedureis performed, or shortly thereafter. This is important to avoid patientnausea during periods of vagus nerve stimulation. Preferably, the pulsewidth is set to a value not exceeding about 500 μs, the pulse repetitionfrequency is set at about 20-30 Hertz (Hz), the VNS regimen followsalternating periods of stimulation and no stimulation, with the secondperiod about 1.8 times the length of the first period in the alternatingsequence (i.e., the on/off duty cycle is 1:1.8).

[0018] The apparatus of the present invention for treating obesepatients suffering from eating disorders includes an implantedneurostimulator for simultaneously stimulating left and right branchesof the patient's vagus nerve via separate lead/electrodes operativelycoupled to the neurostimulator and implanted on the right and left vagiin a sub-diaphragmatic position, the stimulation being appliedcontinuously during a first period, alternating with no stimulationduring a second period, throughout the prescribed duration of thestimulation regimen.

[0019] Accordingly, it is a principal objective of the present inventionto provide methods and apparatus for treating and controlling theovereating disorder, especially in obese patients, by means of bilateralelectrical stimulation of the patient's right and left vagi at asub-diaphragmatic location.

[0020] Another aim of the invention is to provide methods of treatingand controlling compulsive overeating and obesity by bilateralintermittent electrical pulse stimulation of right and left vagi at asub-diaphragmatic position in the patient.

[0021] Alternative techniques include indirect stimulation of the vagus,either bilaterally or unilaterally, at a location near one or bothbranches of the nerve or elsewhere, which has the effect of stimulatingthe vagus nerve as well. This may be accomplished through afferents orefferents, for example.

[0022] It is also contemplated that direct or indirect unilateral orbilateral stimulation applied at or by way of a sub-diaphragmaticlocation of one or more of the other cranial nerves of suitable sensory,motor or mixed fiber types may be effective in treating compulsiveovereating disorder, as an alternative to vagus nerve stimulation.

[0023] Some differences may be observed from stimulator to stimulator inmagnitude of current in the pulses of the stimulation signal, and may beattributable to things such as patient impedance, variation of the vagusnerve from right to left or between patients, and variation in contactbetween the vagus and the electrode implanted thereon from implant toimplant.

[0024] According to other aspects of treatment by stimulation of thevagus or other suitable cranial nerve in the vicinity of the patient'sdiaphragm, beneficial weight reduction is aided by increased activityattributable to release of norepinephrine, serotonin or othermechanisms, increased metabolism and change in gastric motility. Thistherapy may also have beneficial effect in treatment of other disorderssuch as type II diabetes, high blood pressure and orthopedic problemswhich typically co-exist with compulsive overeating disorder andobesity.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and still further aims, objectives, aspects, featuresand attendant advantages of the present invention will be betterunderstood from a consideration of the following detailed description ofa presently contemplated best mode of practicing the invention, byreference to a preferred exemplary method and embodiment thereof, takenin conjunction with the accompanying Figures of drawing, in which:

[0026]FIG. 1 is a simplified partial front view of a patient (inphantom) having an implanted neurostimulator for generating the desiredsignal stimuli which are applied directly and bilaterally atsub-diaphragmatic location to the right and left branches of thepatient's vagus via an implanted lead/nerve electrode systemelectrically connected to the neurostimulator;

[0027]FIG. 2 is a simplified partial front view of a patient similar tothat of FIG. 1, but in which a pair of implanted neurostimulators isused for generating the desired signal stimuli;

[0028]FIG. 3 is a simplified partial front view of a patient in which animplanted neurostimulator and associated electrode is used forunilateral stimulation of only one branch of the vagus nerve;

[0029]FIG. 4 is a simplified partial front view of a patient in whichthe signal stimuli are applied at a portion of the nervous system remotefrom the vagus nerve such as at or near the stomach wall, for indirectstimulation of the vagus nerve; and

[0030]FIG. 5 is a simplified partial front view of a patient in whichthe signal stimuli are applied remotely from electrical stimulatingdevice placed by an endoscope from an area composing the GI tract.

DESCRIPTION OF THE PRESENTLY CONTEMPLATED BEST MODE

[0031] A generally suitable form of neurostimulator for use in theapparatus and method of the present invention is disclosed, for example,in U.S. Pat. No. 5,154,172, assigned to the same assignee as the instantapplication (the device also referred to from time to time herein as aNeuroCybernetic Prosthesis or NCP device (NCP is a trademark ofCyberonics, Inc. of Houston, Tex., the assignee)). Certain parameters ofthe electrical stimuli generated by the neurostimulator areprogrammable, preferably by means of an external programmer (not shown)in a conventional manner for implantable electrical medical devices.

[0032] Referring to FIG. 1, the neurostimulator, identified in thedrawing by reference number 10 is implanted in a patient 12, preferablyin the abdominal region, for example, via a left laparotomy incision.For the preferred implementation and method of direct bilateralstimulation, lead-electrode pair 15, 16 is also implanted during theprocedure, and the proximal end(s) of the lead(s) electrically connectedto the neurostimulator. The lead-electrode may be of a standard bipolarlead nerve electrode type available from Cyberonics, Inc.

[0033] According to the preferred method of the invention, the nerveelectrodes 17, 18 are implanted on the right and left branches 19, 20,respectively, of the patient's vagus nerve at a sub-diaphragmaticlocation. The nerve electrodes are equipped with tethers for maintainingeach electrode in place without undue stress on the coupling of theelectrode onto the nerve itself. Preferably, the sub-diaphragmaticlocation of this coupling is approximately two to three inches below thepatient's diaphragm 22 for each branch 19, 20.

[0034] Neurostimulator 10 generates electrical stimuli in the form ofelectrical impulses according to a programmed regimen for bilateralstimulation of the right and left branches of the vagus. During theimplant procedure, the physician checks the current level of the pulsedsignal to ascertain that the current is adjusted to a magnitude at leastslightly below the retching threshold of the patient. Typically, if thislevel is programmed to a value less than approximately 6 mA, the patientdoes not experience retching attributable to VNS although variations maybe observed from patient to patient. In any event, the maximum amplitudeof the current should be adjusted accordingly until an absence ofretching is observed, with a suitable safety margin. The retchingthreshold may change noticeably with time over a course of days afterimplantation, so the level should be checked especially in the first fewdays after implantation to determine whether any adjustment is necessaryto maintain an effective regimen.

[0035] The bilateral stimulation regimen of the VNS preferably employsan intermittent pattern of a period in which a repeating series ofpulses is generated for stimulating the nerve, followed by a period inwhich no pulses are generated. The on/off duty cycle of thesealternating periods of stimulation and no stimulation preferably has aratio in which the off time is approximately 1.8 times the length of theon time. Preferably also, the width of each pulse is set to a value notgreater than about 500 μs, and the pulse repetition frequency isprogrammed to be in a range of about 20 to 30 Hz. The electrical andtiming parameters of the stimulating signal used for VNS as describedherein for the preferred embodiment will be understood to be merelyexemplary and not as constituting limitations on the scope of theinvention.

[0036] The patient's eating behavior should be allowed to stabilize atapproximately the preoperative level before the VNS regimen is actuallyadministered. Treatment applied in the form of chronic intermittentbilateral nerve stimulation over each twenty-four hour period may beobserved initially to result in no change in eating behavior of thepatient. But after a period of several days of this VNS regimen, adiscernible loss of interest in heavy consumption of food should occur.A typical result would be that mealtime consumption tends to stretchover a considerably longer period of time than that observed for thepatient's preoperative behavior, with smaller quantities of food intakeseparated by longer intervals of no consumption in the course of asingle meal. The VNS treatment should not affect normal behavior inother aspects of the patient's life. A complete suspension of the VNSregimen would result in a relatively rapid return to the previousovereating behavior, ending after resumption of the VNS regimen.Observations appear to indicate that treatment by bilateral stimulationmay be safe and effective in changing eating patterns and behavior inobese human patients, and more generally in human patients sufferingfrom compulsive overeating disorder.

[0037] Animal testing using bilateral VNS has tended to demonstrate thatslowed eating and apparent lack of enthusiasm in food consumption iscentrally mediated and the result of a positive response of inducing asensation of satiety mimicking that which would occur after consumptionof a full meal, rather than of a negative response of nausea or sickstomach.

[0038] The intermittent aspect of the bilateral stimulation resides inapplying the stimuli according to a prescribed duty cycle. The pulsesignal is programmed to have a predetermined on-time in which a train orseries of electrical pulses of preset parameters is applied to the vagusbranches, followed by a predetermined off-time. Nevertheless, continuousapplication of the electrical pulse signal may also be effective intreating compulsive overeating disorder.

[0039] Also, as shown in FIG. 2, dual implanted NCP devices 10 a and 10b maybe used as the pulse generators, one supplying the right vagus andthe other the left vagus to provide the bilateral stimulation. At leastslightly different stimulation for each branch may be effective as well.Use of implanted stimulators for performing the method of the inventionis preferred, but treatment may conceivably be administered usingexternal stimulation equipment on an outpatient basis, albeit onlysomewhat less confining than complete hospitalization. Implantation ofone or more neurostimulators, of course, allows the patient to becompletely ambulatory, so that normal daily routine activities includingon the job performance is unaffected.

[0040] The desired stimulation of the patient's vagus nerve may also beachieved by performing unilateral sub-diaphragmatic stimulation ofeither the left branch or the right branch of the vagus nerve, as shownin FIG. 3. A single neurostimulator 10 is implanted together with a lead15 and associated nerve electrode 17. The nerve electrode 17 isimplanted on either the right branch 19 or the left branch 20 of thenerve, preferably in a location in a range of from about two to aboutthree inches below the patient's diaphragm 22. The electrical signalstimuli are the same as described above.

[0041] In a technique illustrated in FIG. 4, the signal stimuli areapplied at a portion of the nervous system remote from the vagus nervesuch as at or near the stomach wall 25, for indirect stimulation of thevagus nerve in the vicinity of the sub-diaphragmatic location. Here, atleast one signal generator 10 is implanted together with one or moreelectrodes 17 subsequently operatively coupled to the generator via lead15 for generating and applying the electrical signal internally to aportion of the patient's nervous system other than the vagus nerve, toprovide indirect stimulation of the vagus nerve in the vicinity of thedesired location. Alternatively, the electrical signal stimulus may beapplied non-invasively to a portion of the patient's nervous system forindirect stimulation of the vagus nerve at a sub-diaphragmatic location.

[0042] In an arrangement shown in FIG. 5, the signal stimuli are appliedremotely from electrical stimulating device 10 placed by an endoscope 27from an area composing the GI tract 30.

[0043] It is again noted that the principles of the invention may beapplicable to selected cranial nerves other than the vagus, to achievethe desired results. It will thus be seen that a variety of differenttechniques and arrangements may be employed to practice the invention.Accordingly, although a presently contemplated best mode and certainother modes of treating and controlling overeating disorders to induceweight loss in the patient through a regimen of cranial nerve, and morespecifically vagus nerve, stimulation either directly or indirectly at asub-diaphragmatic location has been described herein, variations andmodifications may be made within the scope of the present invention. Itis therefore desired that the invention be limited only as required bythe following claims and by the rules and principles of the applicablelaw.

What is claimed is:
 1. A method of treating obese patients, whichcomprises the step of stimulating a patient's vagus nerve with anelectrical signal applied directly or indirectly thereto at a locationbelow the patient's diaphragm, including programming electrical andtiming parameters of said electrical signal, to induce weight loss ofthe patient.
 2. The method of claim 1, wherein the step of stimulatingthe patient's vagus nerve comprises performing unilateralsub-diaphragmatic stimulation of either the left branch or the rightbranch of the vagus nerve.
 3. The method of claim 1, wherein the step ofstimulating the patient's vagus nerve comprises performing bilateralsub-diaphragmatic stimulation of the left and right branches of thevagus nerve.
 4. The method of claim 1, including implanting at least onesignal generator and electrodes operatively coupled thereto forgenerating and applying said electrical signal to the vagus nerve atsaid location.
 5. The method of claim 1, including implanting at leastone signal generator and electrodes operatively coupled thereto forgenerating and applying said electrical signal internally to a portionof the patient's nervous system other than the vagus nerve to indirectlystimulate the vagus nerve at said location.
 6. The method of claim 1,wherein said stimulating electrical signal comprises a sequence ofelectrical pulses.
 7. The method of claim 1, wherein the step ofstimulating comprises applying said electrical signal to the vagus nerveat a location in a range of from about two to about three inches belowthe patient's diaphragm.
 8. The method of claim 1, wherein the step ofstimulating includes applying said electrical signal intermittently, inalternating on and off intervals according to a predetermined dutycycle.
 9. The method of claim 1, wherein the step of stimulatingincludes applying said electrical signal continuously.
 10. The method ofclaim 1, wherein the step of stimulating comprises applying saidelectrical signal bilaterally and synchronously to both branches of thevagus nerve.
 11. The method of claim 1, wherein the step of stimulatingcomprises applying said electrical signal endoscopically from a portionof the patient's gastrointestinal tract.
 12. The method of claim 1,wherein the step of stimulating comprises applying said electricalsignal non-invasively to a portion of the patient's nervous system otherthan the vagus nerve to indirectly stimulate the vagus nerve at saidlocation.
 13. A method of treating patients exhibiting compulsiveovereating disorder or obesity, which comprises the steps of: implantingat least one programmable electrical pulse generator in the patienttogether with at least one electrical lead having at least one distalnerve electrode and at least one proximal electrical connectoroperatively coupled to said pulse generator, implanting a distal nerveelectrode of a said electrical lead on at least one branch of the vagusnerve at a location below the patient's diaphragm, and activating saidpulse generator to stimulate said at least one branch of the vagus nervewith electrical pulses according to a programmed regimen, to induceweight loss of the patient.
 14. The method of claim 13, includingprogramming the implanted pulse generator to adjust the electricalparameters and application times of the pulsed electrical signal. 15.The method of claim 14, including implanting said at least one nerveelectrode at said location on one of the right and left branches of thevagus nerve in a range of from approximately two inches to approximatelythree inches below the patient's diaphragm.
 16. A method of treatingpatients with compulsive eating disorder by stimulating a selectedcranial nerve of the patient with an electrical signal applied to inducea signal up the nerve toward the brain from a location below thediaphragm, including programming electrical and timing parameters ofsaid electrical signal to control said eating disorder.
 17. The methodof claim 16, including applying said electrical signal directly to theselected cranial nerve at said sub-diaphragmatic location.
 18. Themethod of claim 16, including applying said electrical signal internallyto a portion of the patient's nervous system remote from the selectedcranial nerve to indirectly stimulate the selected cranial nerve at saidlocation.
 19. The method of claim 16, wherein said stimulatingelectrical signal comprises a sequence of electrical pulses.
 20. Themethod of claim 16, wherein the step of stimulating comprises applyingsaid electrical signal to the selected cranial nerve at said location ina range of from about two to about three inches below the patient'sdiaphragm.
 21. The method of claim 16, wherein the selected cranialnerve is the vagus nerve, and the step of stimulating comprises applyingsaid electrical signal bilaterally and synchronously to right and leftbranches of the vagus nerve.
 22. The method of claim 16, wherein thestep of stimulating comprises applying said electrical signalendoscopically from a portion of the patient's gastrointestinal tract.23. The method of claim 16, including implanting at least one pulsegenerator with nerve electrodes coupled thereto into the patient togenerate and apply said electrical signal as a pre-programmed sequenceof electrical impulses for controlling said eating disorder of thepatient.
 24. Apparatus for treating obese or other patients withcompulsive overeating disorder, comprising a pulse generator sanctionedby government authority for implantation in a patient together withelectrode means for stimulation of a selected cranial nerve of thepatient with a predetermined sequence of electrical impulses from saidpulse generator applied to the selected cranial nerve at a locationbelow the patient's diaphragm, for inducing weight loss of the patient.25. The apparatus of claim 24, wherein said pulse generator isprogrammable to enable physician programming of the electrical andtiming parameters of said sequence of electrical impulses.
 26. Theapparatus of claim 24, wherein the selected cranial nerve is the vagusnerve, and said electrode means comprises at least one nerve electrodefor implantation on the patient's vagus nerve for direct stimulationthereof at said location.
 27. The apparatus of claim 26, wherein saidelectrode means comprises a pair of nerve electrodes for implantation ofa respective one of said pair on left and right branches of thepatient's vagus nerve for direct bilateral stimulation thereof at saidlocation.
 28. The apparatus of claim 24, wherein said electrode meanscomprises at least one electrode for implantation internally to aportion of the patient's nervous system remote from the selected cranialnerve to indirectly stimulate the selected cranial nerve in the vicinityof said location.